Method of making lead traps



'(No Model.)

A. A. ROBINSON. METHOD 0F MAKING LEAD TRAPS'.'

" Patented July z, 1889.

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N W.. WML@ NITnD STAT-.ns

ALPHEUs A. ROBINSON, OFOAMBRIDGEPOR'L, MAssAoHUsErrs.

METHOD OF MAIUNGLEAD TRAPS.

SPECIFICATION forming 'pareof Laersraeene No. 406,146, dated Julye, leso. Application filed January @11.889I Serial No. 295,874. (No model.)

To aZZ whom it may concern/.-

Be it known that I, ALPHnus A. ROBINSON,

of Cambridgeport, in the county of Middlesex and State of Massachusetts, a citizen of the United States, have invented a new and useful of a cylinder or tube to its center under press-`4 ure and friction sufficient to heat and fuse the metal and thus cause it to ilow in and form a solid bottom integral with the sides or body of the trap.

Heretofore lead traps have been providedv with bottoms which have not been integral with the metal of the sides of the trap, butv have been formed by bending in. a portion of the lower edge of the body of the trap, and then filling the opening remaining lwith solder or other material. The bottoms of lead traps have also been formed by spinning in the lower ends of the bodies of the traps nearly to the centers and subsequently filling the holes left at the centers by fusing the metal, as set forth in Patent No. 389,761 to Phillips; but this method required two operations, while by my improved method, which consists in spinning in the lower part of the section-of the body to the center of the bottom under sufficient pressure and friction to cause the metal to flow and unite, an integral bottom is formed at one operation.

Referring to the drawings, Figure l represents in section a section of a lead tube from which the body Of the trap is formed. Fig. 2 represents the lower section of the tube' closed in by spinning under pressure to form the bottom of the trap. Fig. 3 is a view in section of the complete trap, representing the top of the lead body as spun upon the ring which forms a section of the coupling. Figs. 4L and 5 relate to a slight modification, to which reference is hereinafter made.

The tube or cylinder a of lead or other similar metal is submitted to a spinning operation, whereby, if desired, its diameter is increased and its lower section a spun in under pressure and friction to form the imperforate or solid bottom a2. In spinning v this bottom the met-al must be subjected to sutiicicnt friction or pressure to cause the vmetal to become heated and to flow during thea@- tion of the spinning, aifdby this means I am enabled to spin a solid bottom, as the metal iiows under the friction or heat to which it is subjected during the spinning operation and unites as it comes or is brought together. The bottom as thus formed is thicker, preferably, than the side as of the body. The

. top rtVl of the body is then united by spinning to a ring, forming a section of the coupling and also the top of the trap. sented in Fig. 3 the ring b as having two recesses b b2, extending about or around its outer edge, and the projections b3 b4, and the upper partof the body of the trap is spun upon this surfaceto tightly fit the same.

In ligs.` 4C and '5 I representa slightly-different form of ring, and it is the one of thc two that I prefer. It has a recess or groove equivalent to the groove b extending about it, and also a projection equivalent to the projection ZJ extending around it. There is also formedon the ring a` recess b5, which receives the upper end of the body and which is formed by means of a downward-extending ring or section h6 of the ring b. This recess b5 is of a size to receive the top of the body, and the upper surface or edge o7 bears against the metal of the ring at bs. The upper section of the body and the ring b are then spun in, causing the metal of the body to enter and fill the recess b to hug the projection b4, and the ring b to bear iirmly against the outer surface ofthe body. (See Fig. 4.) This construction of trap is desirable because it is cheaply made and provides a solid or integral bottoni where a bottoni in two parts has heretofore been used, thus doing away with joints and rendering leakage practically impossible.

So far as I am aware, all lead traps heretofore made have not been provided with solid or homogeneous bottoms-that is, a bottom that is integral with the sides. This is due to the method of manufacture employed, which involves, as a rule, the partial spinning to an extent which varies in degree, but which always leaves a hole more or less large, and this I have repre- IOC hole has been subsequently closed by either the application of solder, which of course involves the use of acid or rosin for the purpose of making a proper union, or by the subsequent melting of the edge of the metal about the hole to an extent to permit it to run t0- gether because of its iiuidity under heat, but for no other reason. The method of closing the opening by solder is defective. If acid is employed, it sooner 01 later eats small holes through the solder or lead, causing the trap to be defective. It is of the utmost importance that the bottoms of these traps be solid and free from any defect which shall produce leakage, and that they be strong. lVhere the hole is closed by the subsequent melting of the metal about the edge, the metal necessary for this purpose is drawn or taken from the metal about the edge of the hole and from nowhere else, and consequently reduces materially the thickness of the bottom at that point-wiz., at the center of the trap and immediately about it. It will be understood that by my method of forming the bottom it is necessary to employ a cylinder or tube of lead or metal somewhat longer than that which has heretofore been used in forming the traps by the combined operation of spinning and soldering or by spinning and melting, and that the i'orming of the bottom is accomplished by the use of spinning devices or tools under a continuous friction or pressure of suicient extent to cause the metal to flow from the time that the spinning operation begins until it is completed, and that this spinning operation is continued under these conditions past or beyond the center oi' the bottom-that is, the spinning-tool is caused to run beyond the center of the bottom, and the spinning operation is continued until the entire body or mass of metal turned in or iiowed in by the spinningtool makes or becomes a portion of the bottom and is homogeneous with the sides7 and that this is accomplished without the use of any additional auxiliary heat excepting that obtained by the pressure or friction of the tool upon the metal, and upon the removal of the spinning-tool the bottom of the trap is complete.4 There is no subsequent application of solder or auxiliary heat of any kind to finish the bottom, and the bottom thus made is thick and substantial throughout, being as Vthick at the center as in any otherpart of the body.

I claim-- l. The improved method of forming the bottoms of lead traps, consisting in taking a tube or cylinder of a sufficient length and in spinning an' end section of the cylinder or tube of suiiicient length to or beyond the center of the tube or cylinder and under a pressure or friction suiiicient tocause the metal to iiow and unite and form a homogeneous seamless and complete bottom, as and for the purposes specified.

2. The improved method ot' forming leadtrap bodies, comprising the taking of a cylinder or tube of sufficient length to form the wall of proper height and a continuous homogeneous bottom and forming the homogeneous bott-om by spinning in under heat produced by pressure or friction of the spinningtool during the spinning operation an end section of the tube or cylinder suiliciently large to form the homogeneous bottom, and continuing said spinning operation under said heat past 0r beyond the center of the bottom, whereby all the metal of the spun-in section forms a part of the bottom of the trap, and subsequent melting or soldering of ihe bottom of the trap to close a hole dispensed with, substantially as described.

ALPI-IEUS A. ROBINSON.

In presence of F. F. RAYMOND, 2d., I. M. DoLAN. 

